The present invention relates to wireless communication apparatuses. More specifically the present invention relates to a wireless communication apparatus incorporating near field communication (NFC) technology.
In a known non-physical-contact communication technology, a compact and lightweight terminal device, such as a mobile phone, incorporates a non-contact IC (integrated circuit) card and communicates with, for example, an IC card reader/writer. See, Japanese Unexamined Patent Application Publication No. 2002-345037. In that publication, a mobile phone incorporates a non-contact IC card and the card of the mobile phone is brought into close proximity to an IC card R/W (IC card reader/writer), thus allowing the information stored in the non-contact IC card to be communicated over electromagnetic waves from the IC card reader/writer.
One short-range wireless communication technology extended to inter-device communication using a communication protocol between non-contact IC cards and IC card readers/writers, called near field communication (NFC) technology, has attracted attention. The NFC technology (an NFC antenna, an NFC circuit, a SAM (secure application module) card, etc.) incorporated in devices such as mobile phones, digital cameras, PDAs (personal digital assistants), notebook PCs (personal computers), game devices, and computer peripheral devices enables any type of data to be exchanged with other NFC-incorporated devices in a short range less than, for example, 20 cm.
Due to its shorter communication range than wireless communication systems, such as Bluetooth and wireless LAN systems, the NFC system provides high security communication. The NFC technology has also attracted attention in view of a different feature from traditional communication technologies, namely, that the NFC technology enables automatic communication between NFC-incorporated devices within or near a predetermined region. The NFC technology also enables data communication at high transfer rates (e.g., up to 424 kbps), at which high-quality images can be transmitted.
A portable wireless communication terminal, such as a mobile phone or a PDA, including a wireless communication interface device incorporating NFC technology enables credit card settlement and access to network content, such as tickets and games, in a simple manner once the NFC-incorporated device is brought into close proximity. The NFC technology is also expected, by content and service providers, to provide a new mechanism for users to access various services.
A wireless communication control device (e.g., a wireless communication interface device) is typically controlled by a controller (e.g., a baseband controller) during communication between a card of a portable communication device and an IC card reader/writer. When wirelessly transmitting or receiving frames, the controller must read and write the information stored in a register of the wireless communication interface device at a high rate. If the controller cannot access the register of the wireless communication interface device at high rate, communication is not established.
A response check, such as polling, required for detecting a communicating party within a communication range is particularly time-critical because response data, such as polling responses, must be transmitted and received in a limited short period of time.
Thus, a high-performance controller is required for performing response checking and other normal processing. However, due to the demands for saving the energy to prolong the operating time and reducing the size of devices, such as mobile phones, it is difficult to incorporate a high-performance controller into the devices.